ci: only trigger e2e test on pr comment

[yanksyoon]

Applicable spec:

Overview

• Only trigger expensive e2e test on Pull Request comment containing: "ci: run e2e". PRs and issues are same types in GitHub hence the issue_comment trigger.
• The required status check for Required E2E Test Status Checks already exists on a repository level, hence this can be safely implemented.

Rationale

• The e2e tests are costly and are resource intensive. When a PR is ready, we can trigger the test run via a PR comment.

Juju Events Changes

Module Changes

Library Changes

Checklist

• The charm style guide was applied.
• The contributing guide was applied.
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation for charmhub is updated.
• The PR is tagged with appropriate label (urgent, trivial, complex).
• The changelog is updated with changes that affects the users of the charm.
• The application version number is updated in github-runner-manager/pyproject.toml.

No code changes, ci changes only.

[yhaliaw]

Does this mean, each trigger of e2e run requires a new comment?
I am unsure if this is a good approach, since it might mean we need to spam the PR with comments.

[yhaliaw]

I think the alt option is to if there is a PR comment that contains the run e2e ci string, then the e2e tests are ran.
E.g., once the PR is almost ready for review we add that comment and see if e2e test is working, and try to fix it on subsequent commits. If e2e tests are not needed for whatever reason, we can just delete the comment.

[github-actions]

TICS Quality Gate

✔️ Passed

github-runner-operator

See the results in the TICS Viewer

The following files have been checked for this project

• lib/charms/data_platform_libs/v0/data_interfaces.py
• lib/charms/grafana_agent/v0/cos_agent.py
• lib/charms/operator_libs_linux/v1/systemd.py

.github/workflows/tics.yaml / TICS / TICS GitHub Action